FILE - In this Monday, April 4, 2016, file photo, Alaska Airlines planes with the company's new livery and tail logo, left, and the old livery used to promote service to Hawaii, right, are shown parked at Seattle-Tacoma International Airport in Seattle. Alaska Airlines slipped past rival Hawaiian Airlines to post the best on-time rating for U.S. carriers in July 2016, the Department of Transportation said Tuesday, Sept. 13. (AP Photo/Ted S. Warren, File)

FILE - In this Monday, April 4, 2016, file photo, Alaska Airlines planes with the company's new livery and tail logo, left, and the old livery used to promote service to Hawaii, right, are shown parked at Seattle-Tacoma International Airport in ... Seattle. Alaska Airlines slipped past rival Hawaiian Airlines to post the best on-time rating for U.S. carriers in July 2016, the Department of Transportation said Tuesday, Sept. 13. (AP Photo/Ted S. Warren, File) (The Associated Press)

Alaska Airlines posts best on-time rating among US carriers

Markets Associated Press

Alaska Airlines slipped past rival Hawaiian Airlines to post the best on-time rating for U.S. carriers in July.

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A total of 21 planes were stuck on the ground longer than federal rules allow, which is three hours for domestic flights. That's the highest number of long delays in more than a year, and it could mean fines for the airlines involved.

The Department of Transportation said Tuesday that 75.2 percent of flights on the main airlines were on-time. That's down from 78 percent in June and 78.1 percent the previous July.

The biggest four airlines finished in the middle of the pack, with Delta best in the group followed by United, Southwest and American.

Nearly 2 percent of all flights were canceled, including 2,300 on Southwest after a computer outage.